Shelves of skulls are seen at the Ntarama Genocide Memorial in Rwanda in 2002. Photo: Antony Njuguna / Reuters

Arusha, Tanzania -

A U.N. appeals chamber overseeing cases related to Rwanda's genocide has reduced one sentence and reaffirmed two others against the ring leaders of the killing spree in the tiny central African republic some 18 years ago.

The appeals chamber of the International Criminal Tribunal for Rwanda on Tuesday reduced the sentence of former military officer Aloys Ntabakuze from life in prison to 35 years for genocide-related charges.

Lt. Ildephonse Hategekimana's sentence of life imprisonment was affirmed by the appeals chamber, as was former businessman Gaspard Kanyarugika's 30-year sentence.

At least 500 000 ethnic Tutsis and moderate Hutus were slaughtered during the 100-day genocide in 1994. The tribunal was established in November that year. - Sapa-AP